Antimatter is any element of matter with an opposite charge than normal matter.
As such, would an antimatter sun conduct fusion normally such that it would it radiate photons, or would it radiate anti photons; or in other words what would the solar wind be composed of?
If needed to narrow down the range of answers, please assume a star similar to Sol, only it is composed of antimatter, and in resides in a suitable galactic environment for an antimatter star.
There is no difference between photons and antiphotons. Photons are their own antiparticle. So the electromagnetic radiation from matter stars and (probably nonexistent) antimatter stars is similar.
The solar wind consists of charged particles. The particles in the solar wind from an antimatter star would have the opposite charge from those from a matter star. For example, the wind would include antiprotrons and positrons (the latter being antielectrons) instead of protons and electrons.
The solar wind is composed by charged particles. Photons travel with the velocity of light in straight lines and do not form a "wind" superposed give the electromagnetic spectrum, including light to see by. The only difference of an antimatter star to a matter star would be that it would be composed by antiparticles of the standard model table. Photons are their own antiparticle. Only if matter meets antimater it will be possible to know the composition of the star.
One of the observations leading to the conclusion that we live in a matter universe is that there is no "solar wind" type coming from antimatter.
If the stars were mixed with antistars in our galaxy, in the region where their two winds would meet there would be annihilation of particles on antiparticles , which would be detected at specific photon energy lines for electron positron annihilation. The annihilation lines observed are within the ones expected in a matter universe. See the answer here.
Antimatter stars would behave exactly like ordinary stars except they would radiate antiparticles instead of particles (or vice versa). So for example if the Sun would radiate an electron, an anti-Sun would radiate a positron.
We can be certain our Sun is not an antistar because if it did, the solar wind would annihilate with and destroy the Earth. Similarly, an antistar in our galaxy would be surrounded by matter-antimatter annihilation that would be readily detectable; the fact that we have not detected them is strong evidence that the entire Milky Way is made of matter.
You can read more about this and the search for antimatter in e.g. The Story of Antimatter: Matter's Vanished Twin by Guennadi Borisov, chapter 6.
